1. Field of the Invention
The present application relates generally to a filter shaker for a filter assembly, a filter assembly having a filter shaker, and a vacuum having the filter assembly and filter shaker.
2. Description of the Background
A tank vacuum, such as some well known wet-dry vacuums, often includes a tank defining a vacuum chamber, a lid covering an opening into a top end of the vacuum chamber, an air inlet to which a hose or other accessory may be attached, an air outlet through the lid, a vacuum pump arranged to force air flow from inside the vacuum chamber out through the air outlet, and a filter carried by a cage extending downwardly from the lid. The filter is in the form of an elongate tube of filter material, such as pleated or un-pleated filter paper or other mesh, forming a tubular wall surrounding an axial bore having opposite open ends aligned along an axis. The filter fits around the cage with a top open end of the bore in air-flow communication with the air outlet and may have a sealed cap at a bottom end of the bore or an open bottom end of the bore may be plugged with a filter retainer that acts to both help retain the filter on the cage and prevent debris from flowing through the open bottom end into the bore of the filter without being forced through the filter material. In some designs, the filter is simply held to the cage by friction between the cage and a gasket built into the filter. The bottom end of the filter and the filter retainer are often suspended spaced above a bottom or floor of the vacuum chamber. This feature allows a substantial amount of debris and other material to collect at the bottom of the vacuum chamber without surrounding and clogging the air pathways through the filter.
Such vacuums are frequently used for cleaning small to mid-sized debris, wet and dry debris, and/or for collecting liquids in home workshops and garages, industrial and manufacturing areas, and the like. Often, the filter is designed to be removable from the cage by, for example, removing the filter retainer from the cage and sliding the filter off the distal or bottom end of the cage. This design feature is useful for changing the filter or removing the filter while, for example, collecting water or other liquids with the tank vacuum.
Frequently, the filter of the tank vacuum can become clogged with debris of varying sizes. A clogged filter can restrict air flow though the filter and thereby limit the efficiency and/or efficacy of the vacuum and/or overwork the vacuum pump motor and cause premature failure of the vacuum pump motor. In the known tank vacuum described above, the debris could be cleaned by removing the filter retainer and the filter from the filter cage, and then cleaning the debris from the filter by, for example, repeatedly knocking the filter against something. However, this process of cleaning a filter can be cumbersome, inconvenient, and may result in dust or debris be spread outside the tank when the filter is removed.
In view of the circumstances described above, the present inventors have developed a filter shaker that may be used with a filter assembly for a vacuum that, in some arrangements, is believed to provide certain benefits and advantages not previously available from filter shakers known heretofore.